GT-40 Fuel Problem (HELP)

[arpen]

I have a 98 GT-40 with 650 hours. All summer its run fine but this weekend it left me in the middle of the lake. It just stopped running. The weird thing is that when I crank it, as long as I hold the key engaged the motor will run, but as soon as I release it, it loses fuel pressure and stops. I changed both relays and that wasn't it. It looks to me like the low pressure pump is an original because its painted just like the motor with the same finish. I haven't taken the FCC apart yet to see what it looks like. Could someone please point me in the right direction.

[triplered]

When you cycle the key to the on position, do you hear the buzzing of the low pressure fuel pump? Have you checked the fuse near the battery? How about the plunger on the lanyard. It would be ideal if you could check the fuel pressure during your attempt to start the boat. No fuel pressure points to the feed pumb (8psi low pressure pump). Fairly common. Call Napa, part number P4594. Good luck!

[DanielC]

Check the safety lanyard.

[arpen]

I did a bypass on the safety lanyard and that wasn't it. When I turn the key on I can hear the low pressure pump run for a second but it goes right off and then nothing. Should it run constantly as long as the key is in the on position?

[DanielC]

The computer will only run the fuel pumps for about a second if it is not receiving a signal that the engine is running. If the engine is not running, the computer shuts the fuel pumps off, this is an important safety feature.
Shutting off the fuel supply is a more effective way to kill a motor than even cutting off the ignition current. It is possible for an overheated motor to run by dieseling even without the ignition coil receiving current. Unlikely, but possible. No fuel pressure, the engine will not run.
When the key is in the start position, the computer will run the fuel pump. This will happen even without the safety lanyard attached.

This post is how to check the fuel pressure.
http://planetnautique.com/index.php?...=fuel+pressure

Pay attention to the wire on the test port in the second picture. Grounding this connection on the test port tells the computer to run the fuel pumps any time the key is on. This is a "back door" service feature for mechanics to use to diagnose fuel delivery and pressure problems.

[wakedude4]

If your fuel pumps are working the only thing to check is fuel pressure at the fuel rail. if you have 40 psi and it holds for 15 minutes than the pumps are fine. If it takes a few times to cycle the key before your fuel pressure guage begins to register, than you may need a new supply pump. But before you go and spend a bundle on the pump, try cleaning the distributor cap for corrosion.

[arpen]

Turned out to be the Safety Lanyard. Replaced it and all is fine. Thanks for the replies